# Study 000F Manuscript

## Title

The Successful Operating Envelope Hypothesis

## Core Question

Do the combined findings from `000D` and `000E` support the existence of a successful operating envelope rather than a simple surface or environment distinction?

## Answer

Yes

## Main Claim

The combined archive supports a successful operating envelope as a better explanatory construct than surface category alone.

## Background

`000D` concluded that the six-year altered-mechanics system adapted through `selective expression` rather than through broad normalization.
`000E` then showed that session-level burden rose when the system was pushed outside its narrowed successful context.

Those two studies together implied a larger question:

`What kind of construct best explains both selective expression and outside-context burden?`

This study tests whether the answer is a `successful operating envelope`.

## Findings

### 1. Successful expression clustered

The later archive did not broaden into free environmental tolerance.
It clustered into a compact successful region.

- `P5` running share: `87.90%`
- `P5` treadmill share: `98.33%`
- late-window running share range: `50.58%` to `62.61%`

### 2. Burden rose beyond the successful region

The October 2025 outside cluster showed:

- running share only `5.13%`
- treadmill-neighbor density only `1.75`
- HR residual burden `13.88 bpm`

That is materially different from the late successful cluster.

### 3. The April boundary case did not behave like a simple surface failure

`2026-04-09` kept outside-context mechanics but showed only `0.69 bpm` HR residual burden while embedded in:

- `91.08%` running share
- `32` treadmill neighbors in `21` days

This is why surface category alone is too weak.

### 4. Surface-only language cannot organize the full outdoor set

Across all outdoor runs:

- burden ranged from `-3.75` to `32.84 bpm`

That means the same outdoor label carried both near-zero and strongly positive burden states.
The archive therefore supports a broader construct than `outdoor equals outside`.

## Conclusion

The stronger program-level conclusion is:

`successful expression in this altered-mechanics system appears to occupy a bounded operating envelope`

This does not settle every envelope axis or mechanism.
It does show that `operating envelope` is a better explanatory pillar than `surface category` alone.